Create Upper Leg Impact Models

Create Upper Leg Impact Models

First set the Type to Upper Leg Impacts. You can chose to create impacts on either the Bonnet or the Bumper.

Automatically create points

You then need to set how you want to automatically create impact points. There are a number of ways to do this:

• Define a distance between points
• Define N points per zone (GTR / UN R127 only)
• Nothing

If you set the Method to Define Distance, you will need to select the distance between points.

If you set the Method to N points, you will need to select the number of points and a spacing factor.

The spacing factor can be in the range 0-N, where 0 will put the impact points on the edge of the zone and N will put them all at the centre. Set it to 1 to space the points equally.

N=2, Spacing factor = 0
N=2, Spacing factor = 1
N=2, Spacing factor = 2

You can set the Method to Nothing, in which case no points will be created automatically.

To create models you will need to create points manually.

Manually create points

Pressing the CREATE MANUALLY button will bring up a menu where you can manually create impact points.

Press the PICK button to start picking points on the vehicle. If you select outside the markup line boundaries then a point will not be created.

Once you have selected all the points you want, press the FINISH button in the window that has popped up.

The menu will be filled with the labels and coordinates of the points created.

If you have created enough points you can move to different pages in the menu to view them.

You can also edit the coordinates by typing in the appropriate textboxes. Only the Y coordinate can be modified as the X and Z coordinates are constrained to the Bonnet Leading Edge line (for bonnet impacts) or Bumper Line (for bumper impacts) and will be calculated automatically.

To view the points press SKETCH ALL or SKETCH

To delete points press DELETE ALL or DELETE

Once you have finished press the FINISH button to close the menu.

Build Models

To build models, the pedestrian markup tool uses PRIMERs model build from a CSV file functionality. You can either write out a CSV file and then use the model build menu or you can build the models directly in the pedestrian markup tool.

For upper leg impacts the angle, velocity and mass of the impactor should be set to is dependent on the location of the impact point on the vehicle and will most likely be different for each one. PRIMER can use the rules specified in the protocol to automatically calculate the correct values and use them to build the models. Alternatively you can specify these values manually, however they will be applied to all the impact points.

If you select the Auto option, you will also need to select the unit system of your model so that PRIMER knows how it should output the velocity and mass values.

The impactor model should contain a reference to a parameter that when modified will change it's mass, e.g. the density field of a material card:

*MAT_ELASTIC
3,&RHO,210.0,0.3,0.0,0.0,0.0

The name of this parameter should be specified here.

For the manual method you need to set the angle, velocity, mass parameter value, and mass parameter name. These will be applied to all the impact points.

Now select where you want to save the CSV file that will be used by PRIMERs model build function.

The WRITE button should now become active, meaning you can write out the CSV file. However, this will only write out data for each impact point (name, coordinates, angle, velocity and mass parameter value). To be able to build the models more information is required (see Appendix N ), e.g.

• The location of the vehicle keyword file
• The location of the impactor keyword file
• Information on the impactor orientation
• How to depenetrate the impactor from the vehicle

This information needs to be written to the top of the CSV file and can be specified here via templates and additional options. The upper legform template can be automatically selected using the following PRIMER preference:

primer*pm_upper_leg_template: <upper legform template file with full path>

The Impactor Parameters menu may be used to create a template file if one doesn't exist. The template file should only need to be created once for each vehicle-impactor combination.

If you don't select a template file comments are written at the top of the CSV file showing what needs to be in the template file:

$ -----------------------------------------------------------------------
$ THE FOLLOWING NEEDS TO BE HAND EDITED
$
$ Remove the '$$'s from the following lines and put in the correct values
$
$ MODELS
$ ------
$$ model, <model_filename>
$$ impactor, <impactor_filename>
$
$ IMPACTOR ORIENTATION
$ --------------------
$$ orient, define, <coord system name/id>
$$ or
$$ orient, nodes, <base node name/id>, <x node name/id>, <y node name/id>
$
$ DEPENETRATION METHOD
$ --------------------
$
$$ depenetrate, contact, <contact name/id>, <dof (X, XZ or XYZ)>
$$ or
$$ depenetrate, partset, <partset name/id>, <dof (X, XZ or XYZ)>
$
$ END OF SECTION THAT NEEDS TO BE HAND EDITED
$ --------------------------------------------

Additional optional information that can be used by the model build (from csv) function may be specified using the Run Parameters menu.

If you do select a template file the BUILD button should become active. If you press this the CSV file should get written out with the information from the template file copied into the top. Assuming the information is correct, the models should get built.